20-year test in N.Y. City
| Scientific comparison will demonstrate cost benefits of stainless steel |
Could lead to a wider acceptance of stainless steel piping
A planned 20-year test program will evaluate signs of corrosion in thin-walled stainless steel piping that
carries potable water to the citizens of New York City.
The program marks the first time anyone has tried to obtain data on the use of stainless steel exposed to the
city's chlorinated drinking water. The findings will be used to convince designers and contractors of the
life-cycle cost benefits of stainless over competing materials. Stainless steel has, for several years, been
used in another major city which has a very aggressive soft water -- Tokyo, Japan.
Given that the sprawling distribution system in New York carryies some two billion U.S. gallons of water per day to millions of citizens, it isn't surprising that the cost of repairs and replacements resulting from corrosion is high. The city's water contains six to eight parts per million chlorides, and experts say this level is likely to remain about the same over the next 20 years. By running the same water through pipes made of several different materials, an objective, scientific comparison can be made.
Such a study was first proposed two years ago, says Richard Hoffmann, president of Hoffmann & Feige. His research team recently located a high-rise building in which to conduct the tests. Costs will be shared by the Specialty Steel Industry of North America (SSINA) and the Nickel Development Institute (NiDI).
All of the building's water will pass through an elaborate system of pipes before entering storage tanks.
Many variables will be evaluated, including schedule 40 welded and seamless stainless steel pipe ( S30400 and S30403), thin-walled, schedule 10 stainless steel pipe (S30400 and S30403) and joints between dissimilar metals (stainless steel, copper and ductile iron). A fire stand-pipe containing stagnant water is also part of the setup.
Different welding techniques will be evaluated, and test samples will be removed periodically and analyzed.
"Typically, someone does a study and presents the results," says Hoffmann. "We, on the other hand, have sought input on how the study should be designed and run."
However, the first results will not be ready until 2003.
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Please contact NiDI consultant Steve Lamb |
